This invention relates to vehicle door latches in general, and specifically to a door latch assembly in which an effectively flexible interior door seal can be integrally molded to and with the relatively rigid plastic housing of the assembly itself.
Vehicle doors are latched when the fork bolt of a latch assembly mounted inside the hollow interior of a swinging door engages a stationary striker on the vehicle body door pillar. The latch assembly fork bolt receives the striker through a hole in the door structure, a hole that opens through the corner juncture of the door inner panel and the door side panel. The latch assembly is mounted by machine screws that run through the door side panel and into threaded bushings in the latch assembly housing. Some clearance is needed between the interior surface of the door inner panel the latch housing to assure proper mounting. A designed or nominal tight contact between the latch housing and the interior surface of the door inner panel could, with expected tolerance variations, potentially jeopardize proper alignment between the mounting screws in the door side panel and the latch housing bushings. This necessary clearance presents a potential water or outside air entry path from the door""s striker entry hole into the hollow door""s interior. It is, therefore, customary to seal around the striker entry hole with a seal on the latch housing.
The typical seal is generally U or C shaped, consisting of rubber, foam or other elastic seal material, and is glued or otherwise attached to the latch housing. The seal is compressed around three sides of the door""s striker entry hole as the latch housing is mounted inside the door. Since the door latch assembly is made up primarily of metal and rigid molded plastic pieces, it is not immediately obvious how a suitably flexible, three sided seal could be integrally formed to or with any part of the latch housing itself, which is why separate seals have been used. These separate seals, besides the additional cost and assembly steps required, are subject to damage and dislodging inside the door as the latch housing is mounted.
The subject invention provides a novel design for a seal that can be integrally molded integrally to the latch assembly, formed from the same relatively rigid plastic material as the latch assembly housing itself.
In the embodiment disclosed, the integrally formed seal comprises three generally planar walls, arrayed in a general C shape around three sides of the striker hole in the latch housing, which generally aligns with the striker hole in the door. When the latch assembly is installed within the door interior, therefore, the same three walls will be compressed against the interior surface of the door inner panel, thereby sealing around three sides of the striker hole in the door. The three seal walls are all molded with thin cross sections, and form an acute angle with the latch housing, sloping outwardly from a lower edge at the surface of the latch housing to a terminal edge.
If each of the three walls were structurally separate, each could be made individually flexible simply by being made sufficiently thin. However, in order to provide a complete seal, the three walls meet at integral corner junctures, and each wall would thereby significantly interfere with the flexing of its adjacent wall, but for a novel design feature. At the juncture of the walls, rather than a sharp, straight corner, a flex joint is provided, in the form of a concave, generally conical or funnel shaped depression, which widens and deepens moving toward the terminal edges of the adjacent seal walls. When the entire seal is compressed, which tends to flex the individual walls away from one another, and away from their corner juncture, the depression of the flex joint is able to flatten out, allowing the individual walls to flex together without retarding the flexing of adjacent walls. The entire seal is thereby rendered effectively flexible, in spite of being molded from a substantially rigid material.